LC75886PW Datasheet, PDF (17/36 Pages) ON Semiconductor – 1/4 and 1/3-Duty LCD Display Driver

LC75886PW
Sleep Mode Functions
Sleep mode is set up by setting S0 or S1 in the control data to 1. When sleep mode is set up, both the segment and
common outputs will go to the low level. In RC oscillator operating mode (OC=0), the oscillator on the OSC pin will
stop (although it will operate during key scan operations), and in exeternal clock operating mode (OC=1), acceptance of
the external clock signal on the OSC pin will stop (although the clock signal will be accepted during key scan
operations). Thus this mode reduces power consumption. However, the S1/P1 to S4/P4, P5/S57 output pins can be used
as general-purpose output ports under control of the P0 to P2, PC50 and PC51 bits in the control data even in sleep
mode (The P5/S57 output pin can not be used as clock output port). Sleep mode is cancelled by setting both S0 and S1
in control data to 0.
Key Scan Operation Functions
1. Key scan timing
The key scan period is 288T[s]. To reliably determine the on/off state of the keys, the LC75886PW scans the keys
twice and determines that a key has been pressed when the key data agrees. It outputs a key data read request (a low
level on DO) 615T[s] after starting a key scan. If the key data does not agree and a key was pressed at that point, it
scans the keys again. Thus the LC75886PW cannot detect a key press shorter than 615T[s].
KS1
*3
1
1
*3
KS2
*3
2
2
*3
KS3
*3
3
3
*3
KS4
*3
KS5
*3
4
5
4
*3
5
*3
KS6
6
6
Key on
576T[s]
Note: *3. These are set to the high or low level by the S0 and S1 bits in the control data.
Key scan output signals are not output from pins that are set to the low level.
1
1
T= _fOSC = _fCK
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